The present invention relates to a method for assessing and/or designing multiple-antenna systems, in particular multiple-antenna systems for use in a motor vehicle. The present invention permits a simplified and improved assessment and design of antenna systems comprising a plurality of antennas.
Current and future radio standards such as LTE, 5G and IEEE 802.11p, use systems with distributed antennas. There exist currently no suitable methods for assessing and designing such systems with a plurality of antennas.
In particular, as regards the use in a motor vehicle, it must be ensured that safety-critical information can be reliably received from an area in front of and/or behind the motor vehicle. Furthermore, it must be ensured that in order to achieve high transmission rates, for example for multimedia data, simultaneous sending and receiving is ensured via multiple antennas (MIMO=multiple input multiple output).
U.S. Pat. No. 6,266,528 B1 discloses the use of statistical methods for detecting defective antennas in an antenna array.
It is an objective of the present invention to propose an improved method for assessing and/or designing systems with multiple antennas.
This objective is met by a method and a computer program product according to the independent claims. The dependent claims refer to preferred embodiments.
The method as claimed by the invention for determining the performance of at least one antenna of a system with multiple antennas comprises the step of dividing a reception area and/or a transmission area of the antenna into a plurality of spatial sectors, subsequently called sectors, of determining at least one value of a performance parameter indicating an antenna performance for at least one sector of the plurality of sectors and of determining a statistical value from the values of the at least one performance parameter. As a result, sectors of an antenna can be selected which are particularly relevant for assessing and/or designing the antenna system. By reducing the complex characteristics of performance parameters of an antenna to statistical values, it becomes easier to perform a comparison of antennas of a system comprising multiple antennas, and therefore antenna systems are easier to compare and/or to design. The method may be implemented in a computer and executed on a computer.
The reception area and/or the transmission area of the antenna may be at least a partial sphere. If the antenna transmits into all directions and/or receives signals from all spatial directions, the reception area and/or the transmission area may be a sphere. If the antenna does not transmit into all spatial directions and/or does not receive signals from all spatial directions, the reception area and/or the transmission area is a partial sphere. The sector may be an area element of the partial sphere. The performance parameter is determined in a plurality of spatial directions, which are covered by the sector.
The statistical value may be, for example, a maximum value, a minimum value, a mean value, an arithmetic mean value, a geometric mean value, a root mean square value, a scattering, a variance, a standard deviation, a mean deviation or the like of the performance parameter determined in a plurality of spatial directions.
The performance parameter may comprise the directional factor, the antenna gain, the directivity, the degree of efficiency or the like.
The method further comprises the step of combining the at least one statistical value of a sector of a plurality of antennas of an antenna system to form a combined value. In this way the entire antenna system can be assessed and/or designed. The inventor of the present invention proposes to initially assess and/or design each antenna individually. Subsequently a system with a plurality of such antennas can be assessed and/or designed. As a result the complexity of assessing and/or designing antenna systems can be reduced and the development time may be reduced.
The step of combining the at least one statistical value of a sector of a plurality of antennas of an antenna system to form a combined value may comprise at least one of the following steps. It is possible to determine the maximum value of a statistical value of a sector of a plurality of antennas. It is possible to determine the minimum value of a statistical value of a sector of a plurality of antennas. It is possible to determine a random mean value of a statistical value of a sector of a plurality of antennas. It is possible to determine the arithmetic mean value of a statistical value of a sector of a plurality of antennas. It is possible to determine the geometric mean value of a statistical value of a sector of a plurality of antennas. It is possible to determine the root mean square value of a statistical value of a sector of a plurality of antennas. It is possible to determine a random scattering of a statistical value of a sector of a plurality of antennas. It is possible to determine a random variance of a statistical value of a sector of a plurality of antennas. The step of combining the statistical value of a sector may be carried out in dependence on the performance parameter, which is represented by the statistical value.
The method may comprise the step of determining optimized locations and/or the required number of antennas dependent on the at least one combined value. This step may be performed interactively and/or iteratively in that, for example, different types of antennas and/or a different number of antennas are used and/or the antennas are arranged at different locations.
The performance parameter and/or the statistical value and/or the combined value and/or the sector may be selected dependent on an application for transmitting a signal. For a security application in a motor vehicle the emphasis is on the forward-facing and/or rearward-facing sector of an antenna array, for example, in order to ensure communication from motor vehicle to motor vehicle. For applications that require a high bandwidth the emphasis is on the directivity and decoupling of channels, which are received via different antennas by means of MIMO. Motor vehicles in terms of this patent application include, among others, land vehicles, passenger vehicles, trucks and motorized two-wheelers.
The plurality of antennas may be arranged on a motor vehicle, whereby an antenna may be arranged on an A-pillar, a B-pillar, a C-pillar, a front bumper, a rear bumper, a roof, a boot lid, a lamp in the front area of the motor vehicle, a lamp in the rear area of the motor vehicle, an external mirror, a boot lid, a window pane, in particular an upper area of a front windscreen, and/or a random area clad with a non-metallic material.
The invention also relates to a non-transitory computer program product which, when loaded into a memory of a computer with a processor and in particular is executed in the processor, executes the above-described method.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.